Even after the powerful speech by President Barack Obama to a joint session of Congress, the fate of health care reform remains uncertain. The White House is having trouble getting Congress to move forward with legislation on terms it favors. And Washington spent much of the following week after the speech discussing South Carolina Republican Rep. Joe Wilson’s outburst rather than the merits of the president’s health care proposal.

Many commentators have recently compared Obama unfavorably with President Lyndon B. Johnson for their respective powers of persuasion and strategies for allowing Congress to work out the details of major bills. But those comparisons miss an important factor that was at work in the creation of the Great Society, something that is missing today. The Congress of the mid-1960s was filled with some very powerful and talented deal makers who helped bring LBJ’s proposals to legislative life. Without such deal makers emerging in the next few weeks, it is hard to see how Obama will succeed.

When Johnson pushed Congress to pass civil rights legislation in the spring of 1964, he ran into a Southern roadblock. Southern conservative Democrats, led by Georgia’s Richard Russell, mounted a filibuster. Although filibusters were rarely used before the 1970s, they had been extraordinarily effective when it came to blocking civil rights legislation.

The only way to defeat the filibuster, Johnson understood, was to persuade Republicans to join him in a vote for cloture. The White House needed the support of Senate Minority Leader Everett Dirksen of Illinois and a bloc of Senate Republicans. Dirksen was a Midwesterner who was known for his aversion to Big Government. He had not been a strong supporter of civil rights legislation.

But Dirksen decided that the time had come to end public segregation in the South. When the House sent its legislation to the Senate, Majority Leader Mike Mansfield appealed to Dirksen to put the national interest over partisanship. Dirksen responded: “I trust that the time will never come in my public career when the waters of partisanship will flow so swift and so deep as to obscure my estimate of the national interest.”

He negotiated with Minnesota Sen. Hubert Humphrey, who handled the bill for the administration, to obtain several changes that included watering down provisions for enforcing civil rights in the workplace. Democrats and Dirksen struck a deal. Dirksen brought over the number of Republicans, 27 in total, that Johnson needed to end the filibuster, and Congress passed the Civil Rights Act of 1964.

This fall, it is hard to see whether Congress possesses legislators of this caliber in either party who could step forward and bring the health care negotiations to a successful conclusion. Senate Finance Committee Chairman Max Baucus (D-Mont.) has often been touted as such a deal maker, but thus far he has failed to find the kind of compromise that would unite the Democratic Party or attract Republican votes. The absence of Sen. Ted Kennedy, one of the greatest liberal deal makers of the post-1960s era, has been devastating for Democrats. Thus far, no Republican has tried to move his or her party toward an agreement.

Without the emergence of a deal maker, it will be difficult to push through successful legislation this fall, even with all the rhetorical skills Obama can offer and even if Democrats try to use the reconciliation process that prohibits a filibuster. In this age of partisan polarization, Obama needs to find the Everett Dirksen of this generation, a legislator willing to take some political risks and make his or her mark in the history books.

Julian E. Zelizer is a professor of history and public affairs at Princeton University’s Woodrow Wilson School. His new book, “Arsenal of Democracy: The Politics of National Security — From World War II to the War on Terrorism,” will be published by Basic Books this fall.